Building a True-Bypass Looper

humfree · Post by **humfree** » 09 Sep 2009, 17:08

I am building a triple loop true-bypass looper. I managed to fit it into a 1590BB enclosure, so I am pretty darn proud of myself.. hehehe..

I bought one of these from LoopMaster years ago, and decided to build a couple of small ones for my backup rig. When I looked at his circuit he had different resistor values for his pulldown resistors. 4 loops with a tuner mute, he had:

18k - Tuner mute - Blue
1k - Loop 1 - Amber
1.1k - Loop 2 - Green
1.1k - Loop 3 - Green
1k - Loop 4 - Amber

It looks to me like he chose these values to balance the color output from the different LEDs, but I just wanted to check.. the 18k throws me. I tend to like my LEDs a little on the bright side for outdoor gigs, but 18x less bright to balance the blue one? Just checkin".. where better?

Thanks!

JiM · Post by **JiM** » 09 Sep 2009, 20:19

Some blue LEDs are pretty bright, i had to stick some duct tape over the one on my Behringer Delay for not becoming blind !

(yes, you still see it through the duct tape !)

There are also a balance to find between the efficiency of the LED, its power rating, and eye sensitivity (depending on wavelength). An example : http://www.nichia.com/specification/app ... 04-8-6.pdf

HydrozeenElectronics · Post by **HydrozeenElectronics** » 10 Sep 2009, 00:25

I bet that it is to balance too. My looper has a Blue, Green and Red Led and there is quite a bit difference in brightness to them. Next time I'll balance them out.